simplify code to return from the end of the function

[wxWidgets.git] / src / msw / dcclient.cpp

diff --git a/src/msw/dcclient.cpp b/src/msw/dcclient.cpp
index c406939a2885d10eaa9b2d48788b54c76cb5bff0..112cf781f5993ecf35984c8ba91086dd08c133d2 100644 (file)
--- a/src/msw/dcclient.cpp
+++ b/src/msw/dcclient.cpp
@@ -1,141 +1,395 @@
 /////////////////////////////////////////////////////////////////////////////
 /////////////////////////////////////////////////////////////////////////////

-// Name:        dcclient.cpp
+// Name:        src/msw/dcclient.cpp

 // Purpose:     wxClientDC class
 // Author:      Julian Smart
 // Modified by:
 // Created:     01/02/97
 // RCS-ID:      $Id$
 // Purpose:     wxClientDC class
 // Author:      Julian Smart
 // Modified by:
 // Created:     01/02/97
 // RCS-ID:      $Id$

-// Copyright:   (c) Julian Smart and Markus Holzem
-// Licence:    wxWindows licence
+// Copyright:   (c) Julian Smart
+// Licence:     wxWindows licence

 /////////////////////////////////////////////////////////////////////////////
 
 /////////////////////////////////////////////////////////////////////////////
 

-#ifdef __GNUG__
-#pragma implementation "dcclient.h"
-#endif
+// ===========================================================================
+// declarations
+// ===========================================================================

 
 

-#ifdef __GNUG__
-#pragma implementation
-#pragma implementation "dcclient.h"
-#endif
+// ----------------------------------------------------------------------------
+// headers
+// ----------------------------------------------------------------------------

 
 // For compilers that support precompilation, includes "wx.h".
 #include "wx/wxprec.h"
 
 #ifdef __BORLANDC__
 
 // For compilers that support precompilation, includes "wx.h".
 #include "wx/wxprec.h"
 
 #ifdef __BORLANDC__

-#pragma hdrstop
+    #pragma hdrstop

 #endif
 
 #endif
 

+#include "wx/dcclient.h"
+#include "wx/msw/dcclient.h"
+

 #ifndef WX_PRECOMP
 #ifndef WX_PRECOMP

+    #include "wx/string.h"
+    #include "wx/hashmap.h"
+    #include "wx/log.h"
+    #include "wx/window.h"

 #endif
 
 #endif
 

-#include "wx/dcclient.h"
+#include "wx/msw/private.h"
+
+// ----------------------------------------------------------------------------
+// local data structures
+// ----------------------------------------------------------------------------
+
+// This is a base class for two concrete subclasses below and contains HDC
+// cached for the duration of the WM_PAINT processing together with some
+// bookkeeping information.
+class wxPaintDCInfo
+{
+public:
+    wxPaintDCInfo(HDC hdc)
+        : m_hdc(hdc)
+    {
+    }
+
+    // The derived class must perform some cleanup.
+    virtual ~wxPaintDCInfo() = 0;
+
+    WXHDC GetHDC() const { return (WXHDC)m_hdc; }
+
+protected:
+    const HDC m_hdc;
+
+    wxDECLARE_NO_COPY_CLASS(wxPaintDCInfo);
+};
+
+namespace
+{
+
+// This subclass contains information for the HDCs we create ourselves, i.e.
+// those for which we call BeginPaint() -- and hence need to call EndPaint().
+class wxPaintDCInfoOur : public wxPaintDCInfo
+{
+public:
+    wxPaintDCInfoOur(wxWindow* win)
+        : wxPaintDCInfo(::BeginPaint(GetHwndOf(win), GetPaintStructPtr(m_ps))),
+          m_hwnd(GetHwndOf(win))
+    {
+    }
+
+    virtual ~wxPaintDCInfoOur()
+    {
+        ::EndPaint(m_hwnd, &m_ps);
+    }
+
+private:
+    // This helper is only needed in order to call it from the ctor initializer
+    // list.
+    static PAINTSTRUCT* GetPaintStructPtr(PAINTSTRUCT& ps)
+    {
+        wxZeroMemory(ps);
+        return &ps;
+    }
+
+    const HWND m_hwnd;
+    PAINTSTRUCT m_ps;
+
+    wxDECLARE_NO_COPY_CLASS(wxPaintDCInfoOur);
+};
+
+// This subclass contains information for the HDCs we receive from outside, as
+// WPARAM of WM_PAINT itself.
+class wxPaintDCInfoExternal : public wxPaintDCInfo
+{
+public:
+    wxPaintDCInfoExternal(HDC hdc)
+        : wxPaintDCInfo(hdc),
+          m_state(::SaveDC(hdc))
+    {
+    }

 
 

-#include <windows.h>
+    virtual ~wxPaintDCInfoExternal()
+    {
+        ::RestoreDC(m_hdc, m_state);
+    }

 
 

-#if !USE_SHARED_LIBRARY
-IMPLEMENT_DYNAMIC_CLASS(wxClientDC, wxDC)
-IMPLEMENT_DYNAMIC_CLASS(wxWindowDC, wxDC)
-IMPLEMENT_DYNAMIC_CLASS(wxPaintDC, wxDC)
+private:
+    const int m_state;
+
+    wxDECLARE_NO_COPY_CLASS(wxPaintDCInfoExternal);
+};
+
+// The global map containing HDC to use for the given window. The entries in
+// this map only exist during WM_PAINT processing and are destroyed when it is
+// over.
+//
+// It is needed because in some circumstances it can happen that more than one
+// wxPaintDC is created for the same window during its WM_PAINT handling (and
+// as this can happen implicitly, e.g. by calling a function in some library,
+// this can be quite difficult to find) but we need to reuse the same HDC for
+// all of them because we can't call BeginPaint() more than once. So we cache
+// the first HDC created for the window in this map and then reuse it later if
+// needed. And, of course, remove it from the map when the painting is done.
+WX_DECLARE_HASH_MAP(wxWindow *, wxPaintDCInfo *,
+                    wxPointerHash, wxPointerEqual,
+                    PaintDCInfos);
+
+PaintDCInfos gs_PaintDCInfos;
+
+} // anonymous namespace
+
+// ----------------------------------------------------------------------------
+// global variables
+// ----------------------------------------------------------------------------
+
+#ifdef wxHAS_PAINT_DEBUG
+    // a global variable which we check to verify that wxPaintDC are only
+    // created in response to WM_PAINT message - doing this from elsewhere is a
+    // common programming error among wxWidgets programmers and might lead to
+    // very subtle and difficult to debug refresh/repaint bugs.
+    int g_isPainting = 0;
+#endif // wxHAS_PAINT_DEBUG
+
+// ===========================================================================
+// implementation
+// ===========================================================================
+
+// ----------------------------------------------------------------------------
+// wxMSWWindowDCImpl
+// ----------------------------------------------------------------------------
+
+IMPLEMENT_ABSTRACT_CLASS(wxWindowDCImpl, wxMSWDCImpl)
+
+wxWindowDCImpl::wxWindowDCImpl( wxDC *owner ) :
+   wxMSWDCImpl( owner )
+{
+}
+
+wxWindowDCImpl::wxWindowDCImpl( wxDC *owner, wxWindow *window ) :
+   wxMSWDCImpl( owner )
+{
+    wxCHECK_RET( window, wxT("invalid window in wxWindowDCImpl") );
+
+    m_window = window;
+    m_hDC = (WXHDC) ::GetWindowDC(GetHwndOf(m_window));
+
+    // m_bOwnsDC was already set to false in the base class ctor, so the DC
+    // will be released (and not deleted) in ~wxDC
+    InitDC();
+}
+
+void wxWindowDCImpl::InitDC()
+{
+    // the background mode is only used for text background and is set in
+    // DrawText() to OPAQUE as required, otherwise always TRANSPARENT,
+    ::SetBkMode(GetHdc(), TRANSPARENT);
+
+    // since we are a window dc we need to grab the palette from the window
+#if wxUSE_PALETTE
+    InitializePalette();

 #endif
 #endif

+}

 
 

-wxClientDC::wxClientDC(void)
+void wxWindowDCImpl::DoGetSize(int *width, int *height) const

 {
 {

-  m_canvas = NULL;
+    wxCHECK_RET( m_window, wxT("wxWindowDCImpl without a window?") );
+
+    m_window->GetSize(width, height);

 }
 
 }
 

-wxClientDC::wxClientDC(wxWindow *the_canvas)
+// ----------------------------------------------------------------------------
+// wxClientDCImpl
+// ----------------------------------------------------------------------------
+
+IMPLEMENT_ABSTRACT_CLASS(wxClientDCImpl, wxWindowDCImpl)
+
+wxClientDCImpl::wxClientDCImpl( wxDC *owner ) :
+   wxWindowDCImpl( owner )

 {
 {

-  m_canvas = the_canvas;
-//  BeginDrawing();
-  m_hDC = (WXHDC) ::GetDC((HWND) the_canvas->GetHWND());

 }
 
 }
 

-wxClientDC::~wxClientDC(void)
+wxClientDCImpl::wxClientDCImpl( wxDC *owner, wxWindow *window ) :
+   wxWindowDCImpl( owner )

 {
 {

-//  EndDrawing();
+    wxCHECK_RET( window, wxT("invalid window in wxClientDCImpl") );
+
+    m_window = window;
+    m_hDC = (WXHDC)::GetDC(GetHwndOf(window));

 
 

-  if (m_canvas && (HDC) m_hDC)
-  {
-    SelectOldObjects(m_hDC);
+    // m_bOwnsDC was already set to false in the base class ctor, so the DC
+    // will be released (and not deleted) in ~wxDC

 
 

-    ::ReleaseDC((HWND) m_canvas->GetHWND(), (HDC) m_hDC);
-       m_hDC = 0;
-  }
+    InitDC();

 }
 
 }
 

-wxWindowDC::wxWindowDC(void)
+void wxClientDCImpl::InitDC()

 {
 {

-  m_canvas = NULL;
+    wxWindowDCImpl::InitDC();
+
+    // in wxUniv build we must manually do some DC adjustments usually
+    // performed by Windows for us
+    //
+    // we also need to take the menu/toolbar manually into account under
+    // Windows CE because they're just another control there, not anything
+    // special as usually under Windows
+#if defined(__WXUNIVERSAL__) || defined(__WXWINCE__)
+    wxPoint ptOrigin = m_window->GetClientAreaOrigin();
+    if ( ptOrigin.x || ptOrigin.y )
+    {
+        // no need to shift DC origin if shift is null
+        SetDeviceOrigin(ptOrigin.x, ptOrigin.y);
+    }
+
+    // clip the DC to avoid overwriting the non client area
+    wxSize size = m_window->GetClientSize();
+    DoSetClippingRegion(0, 0, size.x, size.y);
+#endif // __WXUNIVERSAL__ || __WXWINCE__

 }
 
 }
 

-wxWindowDC::wxWindowDC(wxWindow *the_canvas)
+wxClientDCImpl::~wxClientDCImpl()

 {
 {

-  m_canvas = the_canvas;
-//  m_hDC = (WXHDC) ::GetDCEx((HWND) the_canvas->GetHWND(), NULL, DCX_WINDOW);
-  m_hDC = (WXHDC) ::GetWindowDC((HWND) the_canvas->GetHWND() );
-  m_hDCCount ++;

 }
 
 }
 

-wxWindowDC::~wxWindowDC(void)
+void wxClientDCImpl::DoGetSize(int *width, int *height) const

 {
 {

-  if (m_canvas && m_hDC)
-  {
-    SelectOldObjects(m_hDC);
+    wxCHECK_RET( m_window, wxT("wxClientDCImpl without a window?") );

 
 

-    ::ReleaseDC((HWND) m_canvas->GetHWND(), (HDC) m_hDC);
-       m_hDC = 0;
-  }
-  m_hDCCount --;
+    m_window->GetClientSize(width, height);

 }
 
 }
 

-wxPaintDC::wxPaintDC(void)
+// ----------------------------------------------------------------------------
+// wxPaintDCImpl
+// ----------------------------------------------------------------------------
+
+IMPLEMENT_ABSTRACT_CLASS(wxPaintDCImpl, wxClientDCImpl)
+
+wxPaintDCImpl::wxPaintDCImpl( wxDC *owner ) :
+   wxClientDCImpl( owner )

 {
 {

-  m_canvas = NULL;

 }
 
 }
 

-static PAINTSTRUCT g_paintStruct;
+wxPaintDCImpl::wxPaintDCImpl( wxDC *owner, wxWindow *window ) :
+   wxClientDCImpl( owner )
+{
+    wxCHECK_RET( window, wxT("NULL canvas in wxPaintDCImpl ctor") );
+
+#ifdef wxHAS_PAINT_DEBUG
+    if ( g_isPainting <= 0 )
+    {
+        wxFAIL_MSG( wxT("wxPaintDCImpl may be created only in EVT_PAINT handler!") );
+
+        return;
+    }
+#endif // wxHAS_PAINT_DEBUG
+
+    // see comments in src/msw/window.cpp where this is defined
+    extern bool wxDidCreatePaintDC;

 
 

-// Don't call Begin/EndPaint if it's already been called:
-// for example, if calling a base class OnPaint.
+    wxDidCreatePaintDC = true;

 
 

-WXHDC wxPaintDC::m_staticPaintHDC = 0;
-int wxPaintDC::m_staticPaintCount = 0;

 
 

-wxPaintDC::wxPaintDC(wxWindow *the_canvas)
+    m_window = window;
+
+    // do we have a DC for this window in the cache?
+    m_hDC = FindDCInCache(m_window);
+    if ( !m_hDC )
+    {
+        // not in cache, create a new one
+        wxPaintDCInfoOur* const info = new wxPaintDCInfoOur(m_window);
+        gs_PaintDCInfos[m_window] = info;
+        m_hDC = info->GetHDC();
+    }
+
+    // Note: at this point m_hDC can be NULL under MicroWindows, when dragging.
+    if (!GetHDC())
+        return;
+
+    // (re)set the DC parameters.
+    InitDC();
+
+    // the HDC can have a clipping box (which we didn't set), make sure our
+    // DoGetClippingBox() checks for it
+    m_clipping = true;
+}
+
+wxPaintDCImpl::~wxPaintDCImpl()

 {
 {

-       if ( the_canvas && (m_staticPaintCount == 0))
-       {
-               m_hDC = (WXHDC) ::BeginPaint((HWND) the_canvas->GetHWND(), &g_paintStruct);
-               m_hDCCount ++;
-               m_staticPaintCount ++ ;
-               m_staticPaintHDC = m_hDC ;
-       }
-       else
-               m_hDC = m_staticPaintHDC ;
+    if ( m_hDC )
+    {
+        SelectOldObjects(m_hDC);
+        m_hDC = 0;
+    }
+}
+

 
 

-  m_canvas = the_canvas;
-  RECT updateRect1 = g_paintStruct.rcPaint;
-  m_canvas->m_updateRect.x = updateRect1.left;
-  m_canvas->m_updateRect.y = updateRect1.top;
-  m_canvas->m_updateRect.width = updateRect1.right - updateRect1.left;
-  m_canvas->m_updateRect.height = updateRect1.bottom - updateRect1.top;
-//  m_canvas->m_paintHDC = m_staticPaintHDC ;
+/* static */
+wxPaintDCInfo *wxPaintDCImpl::FindInCache(wxWindow *win)
+{
+    PaintDCInfos::const_iterator it = gs_PaintDCInfos.find( win );
+
+    return it != gs_PaintDCInfos.end() ? it->second : NULL;

 }
 
 }
 

-wxPaintDC::~wxPaintDC(void)
+/* static */
+WXHDC wxPaintDCImpl::FindDCInCache(wxWindow* win)

 {
 {

-       m_staticPaintCount -- ;
+    wxPaintDCInfo* const info = FindInCache(win);

 
 

-       if (m_staticPaintCount == 0)
-       {
-//             m_canvas->m_paintHDC = 0;
+    return info ? info->GetHDC() : 0;
+}

 
 

-               if ( m_hDC && m_canvas)
-               {
-                       ::EndPaint((HWND) m_canvas->GetHWND(), &g_paintStruct);
-                       m_hDCCount --;
-                       m_hDC = 0;
-               }
-               m_staticPaintHDC = 0 ;
-       }
+/* static */
+void wxPaintDCImpl::EndPaint(wxWindow *win)
+{
+    wxPaintDCInfo *info = FindInCache(win);
+    if ( info )
+    {
+        gs_PaintDCInfos.erase(win);
+        delete info;
+    }
+}
+
+wxPaintDCInfo::~wxPaintDCInfo()
+{
+}
+
+/*
+ * wxPaintDCEx
+ */
+
+class wxPaintDCExImpl: public wxPaintDCImpl
+{
+public:
+    wxPaintDCExImpl( wxDC *owner, wxWindow *window, WXHDC dc );
+    ~wxPaintDCExImpl();
+};
+
+
+IMPLEMENT_ABSTRACT_CLASS(wxPaintDCEx,wxPaintDC)
+
+wxPaintDCEx::wxPaintDCEx(wxWindow *window, WXHDC dc)
+           : wxPaintDC(new wxPaintDCExImpl(this, window, dc))
+{
+}
+
+wxPaintDCExImpl::wxPaintDCExImpl(wxDC *owner, wxWindow *window, WXHDC dc)
+               : wxPaintDCImpl( owner )
+{
+    wxCHECK_RET( dc, wxT("wxPaintDCEx requires an existing device context") );
+
+    m_window = window;
+
+    m_hDC = FindDCInCache(m_window);
+    if ( !m_hDC )
+    {
+        // not in cache, record it there
+        gs_PaintDCInfos[m_window] = new wxPaintDCInfoExternal(dc);
+
+        m_hDC = dc;
+    }
+}
+
+wxPaintDCExImpl::~wxPaintDCExImpl()
+{
+    // prevent the base class dtor from ReleaseDC()ing it again
+    m_hDC = 0;

 }
 }